In this research work, a machine vision system is used for evaluating the surface roughness of the turned components by image processing and backlight technique. The surface roughness values obtained by the image processing technique and the traditional stylus probe method are then compared. The comparison results show that the proposed method gives accurate and reliable results on par with the conventional stylus method. Since the proposed method is a non contact method it can be incorporated for in-process inspection of the components without damaging the machined surfaces and also facilitates a 100% inspection of the components in a shorter duration. © EuroJournals Publishing, Inc. 2012.